There are many minilathes on ebay, Warco, Chester, Axminster, Seig, Clarke etc... given that the best 'new' price is about £360 for the 350mm 400W version with a 4" chuck (forget the 3" ones, you cant use the full spindle bore). Throw in a 4-jaw and steady and some tools and your looking at £480 delivered... a secondhand one, year or so old is typically £250-£300 (mine was at the lower end of that), tho you get people asking nearly new prices... but they rarely sell. Anything less than 300W (there are 150 and 250W ones) is a waste of money. MachineMart are way overpriced compared to others... for the same product.

As to size... I've not outgrown mine yet, tho its come close on one or two jobs...