EDIT:
BLOWOUT PRICE REDUCTION! FREE SHIPPING! (lower 48 US states only)
I
have had a total of five Acme Low B cabinets for sale:
The two 8-ohm B4 SI and S1 box/SII internals are still available. Pics are below - All cabs are in great functional shape without any known issues and sound fantastic. There are some basic cosmetic issues, scratches and stuff, a little pilling on some of the carpet, particularly the older ones but not too bad. Nothing glaring our really obvious, visually. I have no prob with these cabs and am not selling them because I dislike them, I just need the cash as soon as possible, not to mention I have too many Acmes. And yes, I have used them all at once before and

Low B4's availale:
Acme Low B4 Series I - 8 Ohms -
$299 USD
Free Shipping! w/Castors, 1/4" Inputs only
Acme Low B4 Series I - 8 Ohms w/Internals converted to Series II (crossover, woofers, tweeter) -
$349 USD +
Free Shipping! (no castors but Speakon inputs only!)
Both of these B4's sound almost identical. I've always noticed very little, if any difference sonically between Series I and Series II Acme cabs to my ear and I've heard and owned several. I've even interchanged them simultaneously depending on the gig and couldn't notice a difference. The one with castors is a little older and sounds a little more mellow overall than the newer one, but I attribute that with age compared to the replacement components in the newer one.
As I understand it, Andy Lewis @ Acme created the Series II initially because he could no longer source the tweeters on the Series I. So he took the opportunity to update the crossover and the appearance of the cab to an all black appearance.
Sold:
SOLD Acme Low B4 Series II - 4 Ohm - $389
Picture for reference: http://www.unf.edu/~n00617175/pics/ACME/photo-7.JPG SOLD Low B2's (Only sold as the pair)
Acme Low B2 and B2W* Series II - 8 Ohm - $520 USD
Pic for reference: http://www.macpulse.com/bass/behringer.jpg FINE PRINT:
Shipping is free from zip 322011 via FedEx Ground to the lower 48 US states. Expedited shipping would require additional cash from you to pay for it but is already pretty expensive for Ground. No Canada or international shipping please. Local sale available, possibly discounted.
Important Note: For the Series I cabinet and the Series I box converted to Series II internals, I have painted both the grills and the metal edging black to visually match the Series II cabinets when I used to stack and interchange them.
Trades or trades + $$$ considered for any of the following:
Raw Woofer Drivers:
Eminence BP102 (8 or 4 ohms), Beta 10, Deltalite II 2510, Basslite S2010, Beta 12, Basslite S2012, Deltalite II 2510, or Beta 8 (8 or 16 ohms) or Delta Pro 8.
Bass Guitars:
Ernie Ball Musicman Bongo 5, Bongo 6 in HH or HS, or Dual HH/HS Stingray 5.
PM if interested, PAYPAL preferred! Thanks!
http://www.acmebass.com/ - Has all the details regarding the cabs, including some differences on Series I and Series II.