I love the Renaissance we've been seeing in Chinese budget knives but I've been a little sad to see D2 dominate the market. I think it's a great alternative to 8Cr13Mov at prices where that matters. (8Cr13Mov is mediocre on both edge retention and corrosion resistance.) In general though, there are just more stainless steels that I'd rather be seeing in these new designs. Here are some alternatives:
12C27 has already been mentioned. I've had positive experiences with 12C27. From my stainless Mora to my Bestech Spike, it's an all-round decent budget steel.
14C28N is a more advanced Sandvik steel that uses nitrogen. Like the other people who've mentioned it here, I really like 14C28N. I've had a few American-made Kershaws and a Ruike knife in this steel. It's been a solid performer.
9Cr18Mov is very stainless but edge retention depends a lot on the company using it. From companies like Schrade or Gerber, don't bother. From companies like Civivi or Real Steel, it's good to go. Civivi offers excellent quality for $40-something. I have no reservations about recommending any of these:
https://www.bladehq.com/cat--CIVIVI--3293#/filter:blade_material:9Cr18MoV
Acuto 440 is a Japanese steel with good corrosion resistance. Kizer uses it in their budget brand, Tangram. I have a couple of their knives and performance seems on par with 14C28N. While not exactly a Wharncliffe, the Tangram Santa Fe is a really nice knife for around $25.
In the $50-75 zone, you can start getting into
VG-10 or
N690. Both are very good and have excellent corrosion resistance. Since you are looking for "entry level", I wanted to focus on some less expensive options that will serve you well.