It all depends on what axle, spring or leaf, shocks, steering etccc...
You can get a dana 44 for as low as $200, or a dana 60 for $800 if your lucky. Then depending on what you replace in the axle(i suggest wheel bearings and seals at least...) coils, raduis arms, or leaf springs.... Junkyards are your friend. Wait for a nice day, and take a walk through your local yard. Some of them dont even know what they got.. My buddy got a front 60 for $200. They had no clue what is was( I think they thought it was a 44). Take your time with the build. small amounts of money over time makes it not as bad..... good luck... by the way, theres a sticky on all of this.....
The price you get the axles for makes a huge difference though. I got my d60 for 500 and it was a lucky find. Read up on some info here then go searching through the junkyard for some good prices on parts or a parts truck. It's not gonna be cheap.
If your asking which will be cheaper? Then its the 6' Skyjacker kit! You can do a sas for cheap but you will be dissapointed and will only wind up redoing things later down the road. So far I am at $1600 in my sas and still have the seering left to buy. So it will be around $2000-2300 when completed after other odd and ends I'm sure. Now keep in mind that includes gears and a Detroit locker. But also I shopped around alot and saved some money by buying things off ebay. Hope this helped. Good luck.
depending on what truck you have and what axle you want to put under it you can pull it off for cheap if you find the right parts, but it just depends on how far you want to take it. Most of the time if your gonna do a SAS you're planing on some serious wheeling and want the axle rebuilt, regeared, upgraded, etc.
so....to answer your question one would need more information. If you simply want a used straight axle under the truck, that CAN be done for cheap, but i wouldn't really call it a huge improvement.
I just started getting all the parts together and it definitely adds up quick. I'm using leaf springs and after everything I think I'll have around 1800 into it, and I didn't have to buy gears and locker.
Like said above, you could do it for cheap if you cut corners everywhere, but then whats the point in doing it.
I wouldn't even consider buying a new ttb kit. If you decide to go that route keep an eye on the forsale forum, there are usually a few for sale. (mine will be in a few weeks:chili
Just for another comparison...Ive got about $1000 in my SAS so far. Its gonna be a hp d60 with chevy 52" leafs. I still have about 4-500 to spend on it too. And i went the "cheap" route on almost everything
I bought the 60 for 350 for the housing carrier and bare knuckles.
scored some free stubs and lockouts, free spindle. bought used inners, used spindle. Just bought new joints and gears and install. Picked up some used springs in get shape for $30! plus theres a bunch of other nickle and dime stuff
I still need spring hangers, shackles, wheel hubs, bearings, rotors, calipers, brake lines, assorted hardware, ubolts, plates, and probably a few other things. So it will probably be 2k when its done.
But it will flex like crazy and be a heck of a lot stronger than ttb.
oh, and thats without the rear lift too.
basically, just figure out if you really "need" a solid axle and go from there
i spent 1100 for a complete truck with the d60. plus 925 for arb and gears, little over a grand for all the rebuild parts. 154 on springs 60 for coil buckets/cups and rad arm caps. 725 for cage arms. like 80 somn on steel. still have to buy steering, breaklines, trac bar, and shocks