Resale prices for Oppo Digital Universal Players

May I ask the forum to explain to me the disparity in the asking and bid prices for various preowned and some new Oppo Digital Universal Players for sale on Audiogon and on another well known resale site?  I'm seeing prices all over the scale.  I know they're no longer manufactured but the asking and bid prices don't seem to make any sense.  For example, there's a BDP-93 manufactured in 2011 with an asking price is $250.00, another one built in 2010 at $310.00 and another at $150.00 similar vintage.  There's a BDP-95 Blu-ray Universal Player for sale at $643.00.  There's a UDP-205 for $3,000.00 manufactured in 2017.  There's a BDP-83SE that's 10 years old with an asking price of $433.00. There are three new UDP-205s with asking prices from $3,699.00, $4,999.00 & $5,295.00 !!  The UDP-205s new were $1,299.00 when they became available.  There's a new UDP-203 built in 2016 at $820.00......new they were $549.00.  I own a BDP-103 from 2014 purchased brand new at $500.00 and it's still in excellent condition.  What is that worth should I decide to sell it here may I ask?