Depends on what you're doing, and what you started out with. For a newer savage with aftermarket exhaust, high flow air filter, I would think not. Reason being that the range is from 138 to 146 (too small). if you're just running stock set-up, this may work to get rid of the backfires and give minor performance increases

Yeah, jets are roughly $3 - $4 apiece and the DJ kit is $50 and you'll still need a bigger main jet than they supply if you're upgrading your exhaust.  Also, the jet numbering between DJ and Mikuni doesn't match.  The Tech Ref forum has a conversion table, I believe.  In my mind, the only nice thing about the DJ kit is getting a needle with multiple notches for adjusting it.  However, you can do essentially the same thing by varying the spacer thickness.  The DJ kit also has a coupon for a free dyno run though how you redeem it and who accepts it I don't know.  In general, if you aren't going to take advantage of the dyno coupon, you can save about $40 by buying a few jets and doing your own spacer mod.