I have earlier used Coinbase and ended up paying $30-40 extra as fees. Also, I didn't like their customer support as they took more than a month to resolve one of my issue.
I have heard that with GDAX account, I need not to pay any fees but the problem is that I am unable to create account on GDAX no matter how many times I try. Kraken doesn't seems to be approving my accounts. Its still pending from past 2-3 weeks.
Changely charges even more than coinbase.
Is there any other way I can buy crypto using USD?
Don't use coinbase. They have shitty customer support, they often ignore your tickets for days on end and you never know when they are finally going to assign someone onto your case. It is a pain in the ass if anything goes wrong. Also, price is generally higher on coinbase ify ou add all the fees.
I actually wouldn't recommend getting any sort of regulated exchange account if you are just trading small amounts because the deposit and withdrawal process is just so gruesome. I would opt for p2p trading, even if it meant that you pay 1-2% above spot for the convenience. But it'll be smooth, no hiccups at all.
You can either use LBC or paxful, i would recommend the former. Spread is usually lower.