Good to invest but in BTC. But if you can't afford to invest in BTC then I would say to invest in trusted alt-coins. But in that case very carefully. Alt-coins are far behind in terms of reliability. But if you are a beginner then start with small invest because it is very high risk. Invest very little money.
Bro. I think you didn't read the OP. he already gave 3 different amounts of money and asked where would you invest if you had that much money. $5000 is way too enough for starting investment in bitcoin, you can't buy a whole BTC with that, but enough for starting trading,
you can buy altcoins too if you want. If I had that much money I would divide them among 100 different altcoins and start trading with them. I would allocate some of the money to join new IDOs because nowadays they are in trend and giving big returns for particpating.
I suppose it all depends on what experience a person has and whether he can really risk that amount. Although I agree that even 5K is enough to make very good money on cryptocurrencies. If you conduct constantly active trading and investments for a short period of time, with enough experience, then even this amount is enough. But if there is no experience, and the only hope is long-term storage of assets or, for example, staking, then for normal income you need more initial capital.