Costs will vary enormously depending on whether you're prepared to do the work yourself or whether you get in contractors. It is impossible to give even a rough idea of costs without knowing the exact size of the garden and the area where you live.

Also if you can find somewhere to put the removed gravel rather than have to take it off site that will effect costs alot.( If there's room somewhere you could perhaps shape it into a bank,cover it with soil and plant up)

If you're not going to do the work yourself get lots of quotes preferably from people who've been recommended to you

If you're buying in services you'd need a professional to lay a good lawn but you could pay a cheap odd job /clearance chap to get rid of the gravel at almost certainly a much lower rate than a proper garden landscaper

Make sure you incorperate a small veg patch when designing the garden...maybe in the form of a raised bed. Let the kids grow some quick salad stuff and also other veg...they'll love it.

I'm sure that if you advertised locally, there would be many takers for your gravel - it's quite an expensive item, I believe. If you put a notice saying "Free to anyone who wants to come and collect it" you could be successful. Worth a try?
I second Andy's idea - get the children involved at the earliest age possible - they will love helping out and the interest will last and develop into their adult years.
I have no idea how much old sleepers will cost any more (I'm really interested to know myself) - I'm sure they aren't the incredibly cheap option they once were, but they do look very attractive, and so much nicer than concrete.
As for your last paragraph, one thing is for certain - you have definitely found the right blog site, and will get hours of useful advice to trawl through, whatever the question - welcome to GoY!

First hello and welcome to GOY.

Yes if you are able todo this yourself you will save money .

And a nice project .

But if you kinda want it done yesterday you need someone to help you.

Yes a an area for the kids to plant as they now get this in schools.

A sandpit for the kids to have fun to.

So looking forward to seeing before and after photos.

Good luck

Grass is not that child friendly - hard compacted grass in the summer is worse than gravel to fall on and it looks terrible when they wear areas down to mud.

Gravel means that they can go out in all weathers - you cannot walk on soaking wet or frosty grass for example.

Certainly add plants, trees, a playing area and the secret area but keep the gravel for a while and then only add grass if you have to.

I have 2 very young kids and the are on the gravel more than grass.

sounds as if the cocrete retaining wall may be there for a reason, ie as in to hold back a bank or some moisture away from the house? maybe look into cladding the concrete to imitate sleepers may be cost effective,and easier long term to maintain. i agree with all the above, my garden has changed several times as the children grew and had different trends,by the way children love summer fruits!!

If you go down the route of building a sandpit (Great idea - I used to love mine and spend many happy hours in it) DO make a cover for it when it isn't in use, otherwise you will find every cat and fox (and lots of other things, too) in the neighbourhood will very happily use it as their own private lavatory.

I think grass or paving's more useful than gravel, specially for children - having spent some time picking gravel out of grazes, it's not something I'd recommend.
As someone else said, need to know the size of the garden (not sure what you mean by 'shallow'), which way it faces (north, south, whatever) and what part of the country you live in (in terms of average yearly temperatures). A couple of photographs would be useful too.

If you wanted to get rid of the gravel after all, try 'freecycle', you will get someone come along and take it, costing you nothing and doing all the work for you! Good luck, maybe you could put some photos on here and get even more advise.

Hello, agree with all the above. You will need to get quotes from reputable sources about replacing wall with sleepers. Another idea is to paint it - do a mural, involve the kids. If the wall is south facing you can also introduce a climbing plant - rose, clematis - or some fruit canes such as raspberries, which all kids love - recommend autumn bliss! A secret area can be created with an archway of honey-suckle, and when they get through that a small playhouse, (if there is space) or a fairy ring created with concrete toad stools painted with red and white spots, with lots of plants around, where they can sit and play! Depending on the light, annuals and bulbs to provide constant year round interest, or some hardy scented perrenials such as lavender, rosemary, phlox, and night-scented stock for the summer evenings.