Should be the same, I would buy the one at the feed store if its cheaper.

Sounds like you have a good plan. Be sure to put down the Alfalfa, Bone Meal and Compost about 3 weeks before seeding. This will give it some time to decompose and start working.
FYI you can put down alfalfa heavy @ 50lbs per 1000sqft.

Some people on this site suggest not to till. Not quite sure why, but I think it brings weed seeds up to the surface????

Thanks for the advice, though I may not have a three week window to wait. I've seen all sorts of guides for when to plant by (temps for the day, temps for the nights, etc.) Any advice?

With how compacted my soil is, I need to till to break it all up. I did half the backyard last fall and learned a number of lessons to apply this year. Tilling didn't bring up many if any weeds. I spent an afternoon in the spring digging up the weeds for a largely weed free yard.

I've seen all sorts of guides for when to plant by (temps for the day, temps for the nights, etc.) Any advice?

I understand, Just try to put down your amendments early as possible and water in for an hour or so for 3-5days after applying. Then every other day until your ready to seed (unless rain is in the forecast). The water will help speed up the decomposition process.

Thanks. I didn't about watering to speed things up.

"Some people on this site suggest not to till. Not quite sure why, but I think it brings weed seeds up to the surface????"

Yes, tilling can encourage dormant weed seed germination. However, I think a bigger problem is that tilling can lead to uneven settling which results in a lumpy lawn.

In general, box blading followed by light scarifying is a better approach than tilling for preparing a new lawn seed bed. If the soil is very poor and requires compost or other amendments to be incorporated, then tilling makes some sense.

-Deerslayer

Tilling is also bad as it ruins any fungal web system already in place in the soil.

Without comparing product A to product B no one can say for sure. But I have consistently compared apples to apples and oranges to oranges between feed stores and nurseries when it comes to things like bagged cottonseed meal, soybean meal, alfalfa meal, and the only difference is a huge markup in price. Often 4 to 5 times higher.

Nurseries love to put it in a smaller bag and charge alot more for it.