Given that you aren't in one of the crazy niches such as Finance, Health, Insurance, or Crypto, most niche edits will be in the $75 - 100 range when you do the outreach yourself. If you're looking for guest posts, those will be in the $100 - 150 range, solid sites DR40+, good traffic that don't link out to just anyone.
When you do outreach you always negotiate, if they ask for $150 offer $100. I always land solid links within the $100 range, I do niche edits only and I try to keep things super relevant so my effort is worth it. It also helps if your site is link worthy, if you have good content and your site doesn't look like shit then you'll have an easier time acquiring links at better prices since no serious webmaster wants to link out to garbage sites.
Most sellers will sell the same links for $150 - 200 or more. You'll get a mark up of ~ 60 - 100% and they will often peddle link farms/low quality garbage, they are doing this in bulk and really don't give a fuck about your site. If you are going to go with a third party link provider, make sure they show you the sites upfront. If they are not going to do that, then that's a hard pass!
You will also come across bigger sites that will ask you $200 - 300, these are good to have links as well but it's hard to shell out this much money when you are looking to build links in bulk. For more powerful links, I sacrifice somehwat on relevancy and manage to get the same type of link for $100 - 150 but on a less relevant site which is still okay because no website on the web has 100% niche relevant links. For stronger links, look at page level relevancy rather than the entire site.