A few 100k is going to be hard in this market, if you don't mind the waiting game then investing in fodder when the market hits a low during TOTY could be a shout but you could be potentially waiting months depending on what SBC's get released, took me 2 months to shift my 88's
If you need the coins for SBC's then BPM is still amazing for creating packs.
Normally spend about 50k a day keeping all minor league's and rares then i'll sell all the prem and la liga bronzes. Got about 300 rares to sell tonight for 350c each when the new icons come out so will get all my money back and i'll have enough cards to complete nearly all the minor leagues for free near enough. Anything not league sbc bound goes into the upgrades and more often then not will typically get about 3-4 prem silvers and then i'll do the 50k from that sbc too. Rinse and repeat and you basically have a conveyor belt of free packs, is time consuming though.