I had a similar situation (although closer to 30k than 50k). My suggestion is to invest all of it and use the cash returns from investments to increase your lifestyle. E.g. if you put it all in a high cash flow investment e.g. ccflx you'll get an extra 3k to spend on yourself each year but will still aggressively save so you can potentially retire early.
A couple of thoughts:
•If it isn't going into a bank account specific to investments, you'll end up spending it.
•If you spend all of it, you've put yourself in a worse place due to lifestyle creep and now need to make that extra money.
•If you spend none of it, you'll wonder why you are working so hard and not seeing the benefits and start spending it.
I would look at:
•debt fund (e.g. ccflx), business development corporation, REIT, or high dividend stock which give you a 9-10% cash on cash return. And use those returns to splurge on extra things. (I would actually not invest in REITs currently commercial real estate is in a tough spot, but mentioned them anyways)
•dividend aristocrats should give 2-4% cash returns but better overall returns than the high yield investments (which probably see limited to no capital growth)
•tech monopolies (in 401k/IRA if possible)
•broad index funds (in 401k/IRA if possible)
•some other alternative investment (real estate, crypto, buying/building your own company/website)
What I ended up doing was increasing my budget by about 400-500/mo, maxing out my 401k and IRA contributions and buying a pair of single-family homes to rent out.