@Kasti - I would recommend thinking about how you want to operate as a domain name investor. I register all of my domain names at GoDaddy (except for the names I buy through NP or some other marketplace that are already registered elsewhere). But do I pay $14.99 for a .com? No. I first started using GoDaddy coupon codes which reduced the price by 30% to $9.98. But then when I was going to "buy" the $5 GoDaddy auctions membership, I saw the GoDaddy Discount Domain Club link and read through that. There was a discount offer at that time for GDDC and so I chose to join the club. As a GDDC member, all .com registrations are presently $8.29 per year, even renewals. Now it's $9.99 per month for GDDC, so you'd have to judge how many domains you want to invest in/renew per month to see if this is worth it for you.
Why do I choose to work with GoDaddy? There are many posts here on NP that bash their practices and fees. But in the end, I choose to stay with them because I am marketing to end users, and most end users only know GoDaddy, not NameSilo or others. Not that the others aren't great companies ... but they are not known by most business owners not in the domain name business. If I was investing only in liquid names to re-sell to other domainers, then I most likely would not be at GoDaddy.