Actually, you can skimcoat yourself - it is time consuming but not hard. (I had no DIY experience!) My entire house had this heavy knockdown texture on the walls. You get a box of Sheetrock drywall joint compound, take some out and mix some water into it to get it easier to spread, and then smooth it on with a big drywall "knife". Let it dry, sand it down, and then repeat. I used a vacuum attachment for a shop vac when doing the sanding and it really minimized the dust. I worked on it every evening and saved a ton of money. If you want, I can post links to the materials I used. I think my actual materials probably cost less than $100. (PS I am a woman "of a certain age" so if I can do this, anyone can!)

You may decide that you can do the bulk of the work and then have a painter come in and do the "finish" coat, which would still save quite a bit of money. The main thing is that if you hire someone to do the skim coating, it takes several trips because each coat has to dry and then be sanded, and it will probably take 3 coats (depending on the original texture.)

I would skim coat it, because you can probably work around all the moldings and outlets satisfacttorily. I just finished skim coating (two coats and sanding)a hall ceiling, and it looks great. To cover it with drywall, as mentioned, requires removing everything and reinstalling. None of this will be easy or quick, but the skim coat will be the best solution with the least pain, in my opinion.

By the time you have it done, the texture will be trendy again. Is it really that offensive? :P

This is very offensive, and the problem is the lower 25% of the wall is actually completely smooth. So it doesnt look right to begin with

I had that in a house I owned once. Hated it and don't blame your for wanting to get rid of it. Skim coating will cause less work with the trim, etc. as was said above.

I had a guest once trip on the stairs, fall against the wall and took all the skin off his knee and elbow. Hateful stuff, that texture.

Yes, I don't think it will ever be trendy; it is too obtrusive. I used Magic Trowel to patch our beloved plaster walls and it was much easier than the normal dry wall trowels for me. Give it a shot; you can always go to plan B if you do not like the results.
Diane