My 2 cents - on the classic worldwide side, bidding for country collections certainly is more competitive these last 12 months, although it's still not too hard to find good lots (for resale or collecting). On the online store side, prices for classic worldwide stamps/sets have increased a bit, but not too much on Hipstamp/Delcampe over the last year (no longer use
ebay, so can't comment there).
Will certainly be interesting to see whether the uptick in the hobby continues as the world moves out of pandemic mode.