Hey guys! I've been investing in Steem Monsters for a very long time now and things are finally starting to look brighter!
My first major investment was when I spent about $1500 USD purchasing 1 max level alpha deck. However, the price for alpha cards kept declining as my next 4 max level alpha sets were purchased at around $2400 in total. I tried to sell them for about $800 each for a very long time. However, no one bought them even though the price of alpha cards kept going up so even though they didn't sell at $800, I'd increase the price to $1000, then $1200 and so on. The first sale I made was last month, or about 4 or 5 months since I last purchased my sets. I sold one set for $1600, then another for $1700, then another for $1900 then my last one for $2200. I still have a few sets but don't plan on selling any more!
The recent boost in market can be credited to DECs and 
Right now each alpha set is worth around $3000!
I can't wait to see what the guilds update will do the the price of DECs hence all cards in general! Really excited about the future :)