So, let's start with numbers.
There are 0001285:0001200 quests, 1630 prestige needed to reach max research. 400 prestige for 100% quests. Let's expect 10 minutes per game for 2 quests, giving 5 minutes per quest means something like ~800hrs to get them (I'm ~38h ingame with 0000007:0000011% so it somehow equals). While playing three games a day, it would require like 3 years to finish.
Well, let's ignore selling map feature. Is it even here now, or am I banned for selling excessing junk here?

There could be more ways to get prestige ..
Selling single map progress, or maybe even single quests? Maybe with progressing formula like 1X for first, 2.1X for second, 3.3X for third, 4.6 of fourth and so on.
Selling items directly for prestige?
Getting prestige for excessing money in each level accumulated? Something like 10g = 1mP?