Babalu, how many times do I have to tell you this, unless the barrel has been properly taken care of before it gets to you it will make nothing but vinegar. A barrel can go bad in a few hours if someone who doesn't know/care is handling it. Stale, sour wine sitting in the bottom of a barrel makes acetic acid at the speed of light. And while acetic acid is a part of the lambic profile it is a minor part. A VERY minor part. Too much of it and you just blew your load on 60 gallons of brew that won't even make good salad dressing.
You get what you pay for. There is a reason a barrel that once sold for $650 is now selling for $40. Even a 'neutral' barrel is still worth keeping for a vineyard because it's still a 'neutral' storage vessel. It's when it turns sour and is only good for holding petunias that they sell it off. So go make friends with a wine-maker and trade him some really good beer for old barrels in good shape.
Oh, wait a minute...
All I want for Christmas is another three day ban on Cape.