Is this your eBay account?
https://www.ebay.co.uk/sch/jon7643/m.ht ... 7675.l2562
Your level of painting basic kits is decent enough. Stripes and hoops are always tricky to do, so perhaps try and stick to plain shirts to start off with? With regards to painting style, either go ridiculously neat (like ShootFirst) or messy like a Kent Housewife... Don't go somewhere in between.
Generally speaking, kits from pre 90s look best on HW repro. For 90s and beyond go with a modern style figure. The type of base you use (as in manufacturer not colour) will make a difference to your eBay listings. Research which bases are popular in both the OS and FISTF games and sell accordingly.
If you're using acrylic paints you have to varnish them otherwise the paint will chip off easily. If you're selling, you don't want a customer to come back to you saying the paint has come off after 1 game.
If you're doing this to make profit, you need to pitch at a price where you're going to cover your material costs, but experience tells me you won't be able to factor in your time. You're currently underpricing your teams hoping for a sale. Have faith in your prices, perhaps list as BIN with offers. Also don't limit yourself to the UK market, you'll get more business selling to other countries. As long as you ship with tracking, it'll be fine.
Also try and find your USP. What's going to make you stand out from everyone else? Is it your painting? Is it custom boxes? Is it thinking outside the box and doing something no one else does?
Your painting style will change over time, you'll get quicker at painting teams and hopefully you'll start to turn a profit from it.
Hopefully this gives you food for thought? I'm in no way trying to put you off and hope the criticism provided can be helpful. The most important thing is that you enjoy painting the figures and have fun doing so.