Warframe

Should I sacrifice a bit of Mastery ranks and trying warframes for plat?

Honestly, never. I'm definitely biased saying this as an MR30, but trying out all of the Warframes and having builds for them is one of the best parts of the game. Really, slots are the best thing you can spend your plat on. Especially once you get into higher level content that starts to randomize what frames you are allowed to bring, you'll want to have a solid roster of heavy hitters to ensure you have something usable. Gauss is def a heavy hitter.

You should be building and using every Warframe unless you don't have Warframe slots for it, for MR purposes.

To answer your question directly, yes gauss is fun. VERY fun. Zoom Zoom.

I'd recommend farming some common parts and selling those for slots instead.

If you have Kahl unlocked, selling archon mods is about the quickest sale. you can get 25-30 for each r0 and 120 for r10. 115 stock per week is just 5 stock shy of 4 mods a week. Augment mods can get 12-15 each too

If you're on the fence, you could farm some regular Gauss at Ur on Uranus, he's mostly easy to farm and craft aside from the open world gems.

If you need plat, Burston Prime is always on rotation and trivial to farm, and is currently attached to some valuable primes like Wisp and Trumna: https://wiki.warframe.com/w/Burston_Prime

Gauss has been my top favorite since they came out, their combat kit is just very useful, fun, and versatile for most mission types for me. But ultimately it comes down to your preference. For me, he's very fluid and has fairly great defense, though the Prime version sacrifices survivability just a little bit.

I mean, 'fun' is personally subjective. What frames do you like more than others, and why?

I really enjoy Gauss because of the speed buffs his 4 gives along with the mini boosts or long dash with his 1. Melee-ing a group as fast as lightning, then immediately 1 dashing to the next group is satisfying af

I almost exclusively use it as my "gotta go fast" frame, and I do find him more fun (and a lot more cool looking) than volt

Might be worth building him to farming relics and then selling the prime junk/sets you get from those relic runs if you don't already have have a loadout that you like using for those. He is one of the better warframes for this and Thermal Sunder is nice to have on the off chance a capture mission turns into an exterminate.

As for fun, that depends on how you like to play. Thermal Sunder on Gauss works fine for nuking content outside of ESO if you have the requires mods/arcanes, and don't mind spamming 3. He's only really fast in the tilesets that are more open/less complex, otherwise you're going to be slamming into walls a lot.

I always have slots for warframes. Even if I need to farm plat to do it. It’s just useful to be able to have options.

Gauss is both really fun and really good. His 2 lets you be practically unkillable when combined with quick thinking, and he's zoomy and goes brrrrr. The thermal transfer augment even lets you give your weapons a big damage boost. That said, you could get regular gauss and use him instead of the prime, the only difference is some mild base stat increases.

Guass is my preferred speed frame. He has worse turning that Volt but runs faster. I find it's more usable to have his forward sprint that Volt's caffeine-OD movement. He also has even more benefits to constant motion than most frames which encourages the whole fast on your feet playstyle.

I have a Gauss frame for the Index that effectively can't be hit by most attacks and parkors slower than it runs.

Gauss prime is my 2nd most used frame. All I really need to say is ZOOOOOOOM!

Depends if you're hurting for Plat and/or if there's something else you're saving up for.

Warframe is a game first and formost. Playing pawnshop shouldn't be the first priority, imo. There's plenty of time for that once Frames and Weapons to rank starts to dry up.

But that's just my opinion.