Hi Champcrow,
The only way to keep your sanity intact is to look at new kit, appreciate it and then wait 18 months to 2 years for it to appear on the 2nd hand market.
I have too many toys to buy the latest of any of them so I pootle about on an old Go200 with a big 8.5m sail, an old ally MTB, and old dirt board nad even my SUP is a used 12' 2" Starboard, but I figure that as time is limited along with my ability and fitness I won't really need much more than these.
As you correctly point out the real joy is when the kids can join in. Mine are excellent swimmers so we all go into the sea whenever we can on anything we have to hand. We MTB round the hills locally and I got as big a thrill of seeing Ben (11) riding his first waves all the way to the beach in Ireland last week as he did.
OK, i'm not riding the coolest kit on the block, but at least I am riding it.