Hello mate, welcome aboard. Firstly, NRL cards prices can be very difficult to provide.
There are lots of variables and now that that the season has ended, Xmas is nearly here and with the current cost of living, the market is not overly strong.
eBay is a very inconsistent way to price cards; you should consider several sources.
You (and your mate) have some really good, high-end cards pictured. The positive news is these are from Select which tend to hold value much better than TLA.
Below is a rough guide. Will you get these prices? Maybe, maybe not, they are great cards, be patient if selling.
2005 Power
HUNT - $400-$500
2006 Accolade
PRINCE is about $250-$300.
WILLIAMS is about $200-$250.
2006 Invincible
Tim SMITH - $350
DALEY - $650-$700
JT - $800-$900
JOEY - $900-$1000
2007 Invincible
SMITH - $900-$1000
HINDMARSH - $650-$750
2012 Dynasty
SLATER $600-$700
The two IP autographed Dynamic era cards of the Johns lads are worth minimal, maybe $5 for Matt, $10 for Joey if in mint condition, which they don't appear to be.
I hope this helps, if you need more advice, sing out.