1891 Hong Kong Jubilee stamps s buying guide

S.G. 48 this is the first gememorative stamp of Hong Kong. The overprint was done by a setting of 12 subjects on sheets of the QV2c carmine SG33. It is believed that one printing characterised by its peculiar carmine shade was only used for overprinting thus unoverprinted stamps in the same shade probably do not exist. It is said that only 50,000 copies were overprinted and many of them bear circular date stamp cancellation on the first day of issue 22 Jan 1891 and subsequent few days. These are c.t.o. since the B62 obliterator was still in use at this period for canceling stamps on covers posted. The story of fights and people being killed on the day of issue trying to buy the stamp is well known.
Interest in collecting this stamp arises because:

This is the FIRST geMEMORTIVE of Hong Kong
The issued numbers are limited and covers are even scarcer; around 20+ are known and 90% philatelic.
Collectors may want more than one copy since there are many obvious positional varieties such as short J, U, tall K
Catalog price (as well as okay prices)of this stamp is rising steadily. In a recent S.G. article on investment in 1954, this stamp in mounted mint condition was priced GBP0.1 and in 2005 GBP250. First day used example with no major rarities such as short J, U, tall K spaced on etc was less than US$30 few years ago and is now creeping towards US$100+ even on the internet!
Beware of fakes!!!
There are many, from crude to professional. But the shadeof the basic 2c is always wrong. The newest and deadliest forgery on mint or unused 2c is done by laser copier so that the characteristics are exactly the same as the genuine overprint particularly when viewed through alowish resolution scan on the internet. Therefore, it is risky to buy a mint copy on the internet unless the seller can guarentee it. Buying a used c.t.o. copy with dates JA22, 23, 24 1891 etc. is safer since the stamp is most likely to be genuine. Buying postally used examples canceled B62 can be risky since ordinally 2c canceled B62 exist in plenty and it is hard to see it on the internet if someone laser copied the overprint on such stamps and sell them through the internet.
How to avoid buying fakes 1891 Jubilees:

Know your Jubilees well
Buy it from reputable sellers who canguarantee it.
There can never be bargains (even on okay!) since there are too many collectors who want the stamp and too few to go round. Therefore, if the price is cheap, there is probably a good reason for it being cheap - a fake or a stamp in poor condition!