This cult following may be driving up prices in some quarters... purchased my daughter's British variant in mint shape for $100.00 last year while my wife's uber mint 20 cost me $40.00 a few years before that and bought 2 well used but solid Phillip's 20's for $60.00.

Have sold 20's for $300.00 plus but that was after I did a lot of upgrading and the higher price was due to the cost of the hand built wheels and other upgrades.

A nice basic 20 should not cost more than $200.00 and maybe $250.00 in some markets like Portland where used bike prices are very high... and a 20 is not even that good a bike to have in such a rainy city unless it has had some significant upgrades.

My wife has had many people ask her if she would sell her Twenty... she tells them that she would take no less than $1000.00.. it was a gift from me while we were dating so has extra sentimental value.