Having bought three or four of these and knockin out ten more DIY built units , I can tell you that the savings on doin it yourself is neglegable.....the cheapest I have been able to get it down to is $498.00usd for a 4 site 13 gallon setup, that is axactly the same components UC uses with a couple of small upgrades, that does not include 1 minute of your time and effort.. You'll have a few days just in sourcing the components, then ordering them and getting them shipped is another ordeal for sure.
One thing to remember is that quantity price breaks wont apply to you in most cases because your not ordering in large lots..like the uniseals, this small quantities your looking at over $6.00 a piece in lots of 100 I still could only get them down to just over $3 plus frieght, the buckets can be found for $12 or so but have a 45 bucket minumum at that price.
When it all said and done you will have about $100-$125 per bucket including everything air/water pumps, lines, seals, lids. etc...and again that is with absolutely none of your time included which is goin to be a couple days on the phone and computer and another day or two actually building and assembling the system.
Tex