Flashbang offers some excellent advice and as he rightly says
Only the very best Mint condition locos and rolling stock in their original boxes, which are also in mint condition (Mint = As sold when new) gain good prices.
Trade buying in values will be around half the retail value of the model. Most traders who are decent will offer you around half the retail value, if you get offered less then don't sell. The trade price allows for a small profit, repairs, finding spares, costs such as petrol etc.
Here are the retail prices for boxed and unboxed mint.
R.555+R.556 Blue Pullman power and dummy car Blue crested front issue, issued 1963-1967 in mint boxed used condition in perfect boxes with instructions etc. £45 retail £22 trade, if used mint unboxed condition £25 Retail, £15 trade, worn condition Retail £20 trade £10
R.555+R.556 Blue Pullman power and dummy car Yellow Fronted non-crested issue, issued 1968 in mint boxed used condition in perfect boxes with instructions etc. £50 retail £30 trade, if used mint unboxed condition £35 Retail, £20 trade, worn condition Retail £20 trade £10
R.555+R.556 Blue Pullman set Yellow front issue, final issue issued 1974 in mint boxed used condition in a perfect box with instructions etc. £50 retail £30 trade, if used mint unboxed condition £35 Retail, £20 trade, worn condition Retail £20 trade £10
R.555C Blue Pullman power and dummy car BR Blue & Grey yellow fronted issue, issued 1969-1972 in mint boxed used condition in perfect box with instructions etc. £65 retail £30 trade, if used mint unboxed condition £30 Retail, £22 trade, worn condition Retail £22 trade £11
R.555C Blue Pullman power and dummy car Blue crested fronted issue, issued 1965 Worlds Toy fair special limited edition in mint boxed used condition in perfect box with instructions etc. £165 retail £80 trade, if used mint unboxed condition £25 Retail, £20 trade, worn condition Retail £20 trade £10
Sets
Standard R.52 Blue fronted Blue Pullman set in mint factory crisp conditon £100 retail £55 trade, used condition £45 Retail £25 trade, worn £30 retail, £15 Trade.
Coaches
R.426 Blue Pullman Blue livery coach. Mint perfect boxed £40 Retail, £20 trade, unboxed mint £25 Trade £15, worn £20 trade £12.
R.426 BR Blue and Grey livery Mint perfect boxed £50 Retail, £25 trade, unboxed mint £30 Trade £20, worn £22 trade £14.
Mint sealed limited issue World Toy Fair BP's in the later tray style boxes fetch hundreds, they are like hens teeth to find.
Here's the limited worlds Toy Fair 1965 R555C edition that has remained sealed in it's box from new.
Worth just over £500 in this condition. It's not for sale. You don't find them for £4-9shillings and six pence today!

