Where they mint boxed undamaged items Chris? Values are dependant on condition and whether the model has it's box or not. Mint boxed items fetch more even if there are dozens of the models about because people used to throw the boxes.
Sealed items in original polyseal untouched since they left the factory fetch a lot more and have a market all of their own
Current prices based on current market, Ramsay's guides and Train Fair prices for mint clean undamaged items in good boxes complete,
Hornby(Not Tri-ang but using the old Tri-ang L1 body) 2p(1973-1975) £45 mint boxed
Tri-ang L1 BR Green £70 Mint boxed
Hornby Ivatt 2MT BR Green £40 Mint Boxed
Tri-ang B12 Black values dependant on model R150S £35 Mint Boxed R150NS £50 Mint Boxed
Tri-ang BR 3MT Green £55 Mint Boxed
Tri-ang Jinty values dependant on model first issue with british Railways on side tanks worth £150 Mint Boxed, normal models without smoke £35 Mint Boxed
Tri-ang Hornby Flying Scotsman A3 dependant on livery and model LNER A3 £35 mint boxed, BR non corridor tender A3 Red nameplate £45, BR non corridor tender A3 Black nameplate £40 BR A3 with Corridor tender rare £45 mint boxed
Condition is everything and models in lesser condition without boxes, steps broken, worn out etc will be worth a lot less.
Mint sealed items untouched
will attract much higher prices
for instance
Tri-ang-Hornby LNER A3 still sealed in it's box with outer sleeve in good condition £130
Hornby 2p(old model) still sealed in it's inner tray with good upper and lower box £105
These are of course exceptions to the rule as such items are very rare and sedlom come up for sale to the general market.
Mint boxed Wrenn of course fetches silly money and some models are very rare, rarer models tend to be worth more even unboxed.
EBay cannot be used as a guide to pricing as it doesn't reflect Ramsay's gudies and the toy and train fairs. Ebay is an online fleamarket in a way, and like msot auctions it all depends on the way what someone is willing to pay for something and who many people are bidding so values on EBay are unpreditcable and unreliable as a rule. Note I say as a rule.
This linky will take you to a site where values for first rate Tri-ang can be seen.
http://www.cbtoys.co.uk/showtoys_f.asp?collection=58