Call someone out that gives a free quote & then compare to what it would cost at building supply store. I did mine years ago & had help lifting rolls up to me. I suppose you could go up & measure each length you need & go down & cut it but my knees aren't that good. It depends on how much room you have in your attic also,if you have to crawl around to get anywhere good chance you could get hurt. But if money is tight I'd lay the 1st roll in closest to where you enter attic space. Then I would get some boards,smooth pine, 6 ft long & 12 in. wide & 1 in. thick & NAIL down(3 in. nails2-3 nails going in each stud so it has about 9 nails in it & is secure) for safety to studs, making a small platform so any time you need to go up there you have a safe place to sit, leave bottle of water,sit or lay down if you crack your head or hit your elbow or get a cramp in your leg. A couple hundred dollars in wide boards makes attic so much safer & much cheaper than trip to hospital because you had no place to go when you got hurt to get your bearings. Add the boards as you move out into the attic, nailing them in place before you leave them,if you step on unnailed board you could really go flying & get hurt.. I have "path" to both large screened vents, area where 2 bathrooms plumbing connections are, where the furnace is, we put in a loft for kids to play in & it had a light fixture with outlet so I plug in 50 ft. extension cord with light bulb & carefully put it over 1 of braces making sure cord is nowhere near where I'm working so I could trip over it,moving as I work out to another area. Roll insulation is what I used & I scooped up the loose stuff with a plastic dustpan & put it in the narrow areas & hard to reach areas. Worst for me was getting the stuff to lay down under eave areas as I wanted to back out & get out of there. I don't do well in tight places so I think if you have that problem take a cane(like older folks use) or pole about that size & push it back into the area needed. Yes you can go through the ceiling, neighbor did so if you are not pretty agile I wouldn't attempt it. Also the fiberglass is very hard on the lungs. I couldn't stand the masks so I took a large man's hankie, think old movie-bandits..fold in triangle & large area of fold goes over your nose & hangs down & you tie it behind your head. So the pro might get materials at a better price than you but why would he give you a break, that is how he makes his money or at least part of it. When you buy a radiator cap it costs $4.95 & you put it on yourself, Garage buys it & out here most times it will cost double or $10 plus labor to put it on. Same thing happens with lot of DIY jobs. Good Luck!By the way I'm a woman so you can do it which ever you are. I think I pointed out the ugh parts & being prepared you should do fine! Oh, put a little LED flashlight in your pocket in case you break the lightbulb you'll be able to see where you are going to get out of there.

I had my attic insulated with blown FB to 10". It took 3 hours total and was $861 total
I was really pleased it was done as it added great heat value.

Usually blown in insulation packs down as years go by so it loses some of it's effectiveness. Same thing happens in walls. But it is your choice. 10 in. is a lot so if it packed down would take awhile. You would have to check to see if they actually covered the whole attic & difficult to do before you pay the guy. Our new house got done in morning & when I came by to see what they had done that day a guy in a suit was coming out of attic, I asked who he was-insulation inspector so I told him I wanted a look before he left. I went up & most of it was within 15 ft of the opening. Told him to come back up, he couldn't believe it. I told him the workers must know you show up in a suit!! Should have on overalls or something & be prepared to crawl to far corners. They redid it & did a pretty good job.

I would go with the blown insulation. Just make sure they do a good job. If you do it yourself then you've got to squeeze into tight spots and you have to worry bout falling through the ceiling while hitting your head on nails from the roofing and that does not feel good!

My local box store had a low price on fiberglass batts, plus a rebate. I added R-25 to my whole attic, around 1000 SF, for $280 total. This went on top of the existing 3.5" of loose rockwool (R-10 ish). I also installed pre-fab vent baffles and sealed up cable penetrations with expanding foam, roughly another $80.

If you do use batts on top of existing, make sure they are unfaced.