Well, that package isn't right. You don't have reverse cut 8.8 gears in the front. You have a Dana 35 yes?
Second, that's not a good price to my way of thinking if the picture is of the whole kit, although perhaps the reverse cut 8.8 gears for the front are expensive.
I got 1/2 of that kit for $243 and it wasn't any more than that for the front gears when I did the D44.
You need a rebuild kit, and for the rear I would do axle seals and bearings while you're in there if you've never redone them. That's extra cost and admittedly optional but it's a good idea. Make sure you get the correct axle bearing kit. The 31 spline (Explorer, F-150, and FX4 L2 Rangers) use one set of bearings and the normal Ranger 28 spline uses a different, smaller set. Ditto axle seals.
On the c-clip 8.8 solid axle there are no seals on the diff. The oil bathes the axle shafts and bearings and the axle seals at the ends of the tubes are the sealing for the whole assembly.
The 8.8 differential bearings, ring and pinion, and shims are all exchangeable between 28 and 31 spline models.
Keep track of your bearing caps and orientation. The area where the bearing cups seat is machined in-place on the axle and you have to keep the bearing caps in their original positions and orientation when you reassemble.
I have never done a front Dana 35 so I have little to offer, other than to suggest any kit needs differential axle seals and many master kits for differentials don't include them. They're not expensive though.
Are you doing this yourself?
As far as the 8.8 portion, you can get the full kit except axle bearings and seals from Brenspeed on eBay for around $250 including shipping. That was for the higher end Motive gears (their performance line).
Not sure the best place for a dana 35 kit.