Ok, you could go really cheap. I did. Et voila, here is my long-suffering Ammaco Dresden complete with trailer. Although this cost a mere £150, bits drop off at an alarming rate - the left crank fell off after 6 miles! At least any aftermarket part is an upgrade, and H***rds have served me well. But unless you fancy replacing stem, saddle, crankset, chain, tyres, pedals and bottom bracket through necessity rather than whim, get something decent!
I should say in its defence that everything not mentioned has performed with total reliability and ease. The 7-spd Tourney revoshift gears deserve a particular pat on the back as the most faultless gearchange I have ever known. At the back at least. the front changer is totally useless. Hey ho, on we go...