I really loved the game. It took me 20 hours to complete, which includes a restart after some hours when I had unlocked more interesting characters than the starting lineup. I'll have to go back and finish it with the ones I missed in the future.
The game was a lot of fun, and definitely worth the asking price. It made me smile many times, what with all those wacky references to other games and developers. I bought the Deluxe edition to support the developers as much as I could, as I had researched the game prior to buying it, and I'm glad I did. The extra gold you start with is nice (but doesn't provide any sort of advantage other than when you get a full lineup but let's face it, it doesn't matter).
If you're on the fence, then just go ahead and spend the 10 euro or whatever the price is in your region. It's a fun throwback to the golden ages of gaming, and it's just well done through and through. I doubt very much you'll regret it. Don't worry about the ingame cash shop. I never used it, and NEVER had a reason to. You earn redicilous amounts of gold in this game just doing the main quest line, and the extra gold you can buy for real money is so useless, I'm puzzled why they added it at all.