What do you consider 'cheap'?
My last kit was $128 (BGF 66cc) shipped off eBay. About to buy another one at $136 this weekend. What I find and this may be a tip and maybe not, is to add several kits to your 'watch list' that are in the low range buy it now. Leave them in your 'watch list' all the time and the products will come down in price. What you will see over a matter of weeks is that they will discount them to you, 10% them more. Commit to buy when you think you cant wait any longer and/or the price has been reduced to what you're comfortable with.
If I'm to pay about $200 bills, would spend a bit more for 4 stroke. IMO.