I agree with the Kmart ones – I found these very comfy and reasonably priced!

I found my running bare leggings/tights were amazing and so comfy. A bit expensive but worth the money.

Also; found some good ones in thrift stores; well worth looking because they were used for a relatively short period of time and were in good condition.

Surprisingly Kmart high waisted leggings, they’re like $10-$15 and are super comfy

Sorry I can’t really advice as I never bought maternity leggings, but know Bonds have some good options indeed

Bonds make good quality ones, not sure about their comfort though.

I went with reasonably priced ones from department stores; did not want to spend lots of money on them for a short amount of time worn.

Bonds have some great maternity leggings options and regularly have sales online to look out for. Kmart are cheap and comfy for around the house, or an oversized tshirt wearing out. I did find they will show through the moment too much stretch is happening.
I almost bought from emamaco but was weary of some product reviews regarding service and quality.