There really isn't any "inexpensive" way to make 50 gallons of wine from fresh grapes, nor is there a recipe, 10 people will give you 10 different variations, but be aware, be careful that the advice you take is from someone that has years of experience and has been successful.
Have you decided on what varietal of grape you would like to make?
To make 50 gallons of wine, you'll want to start with 20 or so lugs of grapes, I would highly recommend California or Washington state grapes, each lug will weigh 36 lbs, 36 lbs of grapes will make approx. 2.50 gallons of finished wine. The total weight will be 720 lbs and this should give you 67(ish) gallons of wine, subtract some of that for topping off, and possibly if the grapes don't render exactly 2.50 gals per lug.
The price per lug will run you in the neighborhood of $55.00 - $65.00 per lug, so you're looking at approx $1200.00, plus you'll need to factor in:
Yeast
Go-Ferm
Enzymes -(Lallezyme, Opti-Red, Booster rouge)
yeast nutrients (Fermaid K & Fermaid O, DAP possibly)
Malolactic Bacteria
Opti-Malo
Oak
Crusher -Destemmer
Press
Fermenting buckets
I personally wouldn't use the barrel that had raspberry in it for a few years, the barrel is probably neutral, and would you really want a beautiful batch of Cabernet or Merlot, or a really nice Bordeaux blend to have a strong raspberry taste, not to mention any other problems that might be resident in that barrel.
If you select the right yeast that will complement the grapes, you will have the natural berry flavors come out of the wine.
Personally, I'd start with 15 gallons this fall, you can purchase 50 liter Hungarian barrels fairly cheap, the cost of the grapes would be in the $450.00 range, much less "sticker shock".
I'd be more than happy to help you out if you choose to pursue this.
I hope that this helps.