I have the Stewart one that is thermostatically controlled and starts at about 15C up to about 25C. It cost me £75 but that was sometime ago

I use my airing cupboard and the baggie method. Put some coir or seedling mix in a zip bag add water and then the seeds and leave them in the cupboard for a few days and most seeds will have germinated. If you have small seeds then putting them in an tray (an old plastic tray that rasps and strawberries come in or even better the small ones blueberry comes in), wrap that in a large freezer bag and put that in the airing cupboard. My Dhalia seeds took 2 weeks to all pop up that way. As long as you have a sunny windowsill then you do not need a propagator afterwards.

Thank you to you both for repling - i havnt got an airing cupboard , can you put the bag method on a window sill? i think id like to try this before getting a propergator.

If you open the bag during the day, then the bag will work up at the window. If you leave the bag closed then the sun will make the seeds bake and sweat.