What to buy and how much to pay
Buy a runner and accept no excuses! If it runs but makes lots of thrashing chain noise walk away; cam and balancer chains are infamously difficult to find. A so-called complete bike in boxes is honestly not a viable project and its only real value will be as a parts donor. If you insist on hurling money at dismembered remains, figure on £500 tops. A non-runner is arguably only worth £250 more. Scruffy but quiet running examples seem to generally fetch £1200-£1500 and it’d have to be a very good example to make much more than that. Mint originals might possibly go for between £3500£4000: don’t get conned into believing just because TX500S are rare they are worth more… they aren’t! If authenticity is important ensure frame and engine number match. Also be aware that 1976 C models and onwards have a two-piece cylinder head; the earlier examples have a three part top-end. Note there are only three models to choose from if you want the early versions. For 1973, the TX500 came in orange or blue with large black and gold decals on their tanks; a handful seem to have been produced in dark green. The 1974 TX500A is much more restrained with a simple double white line along the lower tank edge and in mid blue. 1975 XS500BS come with swirling gold graphics over a colour named Marge Brown which you either love or hate. For what it’s worth our money would go on the 1973 orange original.