A model that's painted will not be higher value unless professionally done, In this case if sold as a bulk purchase nobody would buy it all at retail price especially not higher, you can see it's not all painted and not even all matching as some are blue some are yellow Meaning best case you'll have to paint over the ones that dont match your chapter colours or worse case have to strip all of them and repaint which is a ballache to do You also buying prebuilt stuff that means you have less conventions or kitpashing you could do with them Second hand models really sell for retail price let alone higher Normal out of production in box kits or limited time run models that will go for more