I just helped my nephew get steam premium - to add friends etc - and thought i'd just share this with some people who may not have premium.
So, these are possible methods for anyone, all ages, can be done without credit cards. AND do not need your steam-related ID or any info, just make a fake email account for this and it'll still work since it gives steam codes.
For TF2 Premium:
1) Get a friend of yours who trade/already have funds in their steam account to gift you an upgrade to premium item from the store, and pay him back the cost or just get it as a gift.
This is the only way to get in through in-game item, the rest below CAN get you steam & TF2 premium, if you use steam funds to buy an item from tf2 store (any cost)
Steam Premium using $ cash:
1) Buy a gift card from the store
A list of where you can purchase Steam Gift Cards (Singapore)
1. Game Stores
Game stores are the most likely to sell Steam Gift Cards, although at a price premium. Visit your closest shopping centre and you’ll likely find one that sells Steam Gift Cards.
Local LAN Shops are likely to sell Steam Gift Cards. Prices are comparable to those offered at Gaming Stores.
3. Online stores/selling platforms
Online sellers are generally less trustable but you are likely to find cheaper prices from here than the other alternatives. You could purchase gift cards from sellers on platforms like Carousel and pay them in cash.
4. Debit Cards
This is the best option due to convenience. You can easily get a Debit Card from the bank for free and use it to purchase Steam gift cards/codes online (or direct from Steam).
Steam Premium without using cash:
1) Ebonus.gg (get 50 coins for clicking tt link, and making an account)
1. Set up account
2. Confirm account and simply start doing surveys - earns more coins
3. If you wish to watch videos to earn coins (most slack), i would suggest you download tampermonkey and then search for ebonus.gg scripts to use so that it will auto click next video with the tab open.
4. Earn enough coins to convert coins to steam credit - this may take a few days because surveys may be drained out etc, but it's free to earn and you only need $5 and then purchase an in-game item for premium
5. If the game code or reward you want is not offered, you can send a ticket in for it to be offered on the site. The response is often within 24hours, flexible and rather friendly!
advice: always set up your profile, i.e know exactly what are you income level, age, industry, and STICK TO IT for surveys (some may tell you they are looking for anth profile and allow you to continue, i'd suggest altering only at this point), only do surveys that reap larger rewards
1. Really easy to set up account, just enter email
2. Same thing as above, uses a different pricing system (i.e coins/points to real $ comparison differs)
I think those 2 sites are the more popular and legit ones (tried and tested!), you may want to just see what other game cards/codes that the two sites offer and then focus on the site that has what you want or you feel is more comfortable using. Good luck prepping for your Christmas Gifts!
*Comment below if you're interested in how to effectively earn coins for ebonus.gg cos i kinda learnt the trick already and have 20k coins, will add anth guide!