It really depends on what you want to do. A lot of those requirements are for classical harping, pedal markings, etc. I've been scoring harp music professionally for about 18 years, and there are symbols in place for harp notation, plus good workarounds which also serve the purpose quite well. I run my own publishing company (small though it be), and some of its material is on the ABRSM and Trinity syllabuses/syllabi (take your pick), also the Royal Irish, so it does meet industry standards. Sibelius has been my weapon of choice.

I have friends who use less expensive software for their harp books, and it seems to work fine (I've seen/bought/played a lot of their stuff) though I'm sorry I can't provide specific details on their programmes. But most of the folks I know in that line tend to have Sibelius or Finale. It's not just a matter of symbols, it's also stuff like cross-staff beaming and odd voicing/stem configurations. (That word "affordable" may be a sticking point, I suppose; but we all manage to stump up for computers and smartphone and tablets. I think it pretty much boils down to: one can afford what they want/need to afford.)

But I have not liked Sibelius' upgrade versions for quite some time, and am now not getting them any more. The actual scoring capabilities just get wonkier and wonkier as They mess them about to suit the needs of their precious Pro Tools. But it isn't working. Avid is not in great shape and has downsized yet again.

I'm interested in the new programme Daniel Spreadbury and the Finns (the inventors of Sibelius) are currently developing for Steinberg. At least Daniel will listen to you, and responds to queries promptly. He's a Facebook friend, and publishes a periodic development diary, so I will eventually go with his product. But Sibelius has adequately served my purposes for a long, long time, and continues usable, if increasingly irritating.

So I'd say hang fire and when I see what the new one is like, I'll start a thread. (It'll be awhile though - it's still in beta.)