Nobody can predict what is going to happen with BTC or the whole cryptocurrency eco-system in general. There's still potential for the technology to take off and gain widespread adoption, just as there's the potential for all the big players to lose interest and move on to something else.
If you want to 'invest'(I prefer gamble, or play at this point) - go for it. Just like every fad there are groups of people who believe strongly in the idea of the thing, and those who just want to get rich off of the thing.
At this point nobody has definitive answers on the future of BTC.
Public interest / perception is the biggest factor at play here. There can be literally 0 uses for cryptocurrency, but if news outlets are telling a layperson to buy it, they'll buy it. As long as the big players are interested in keeping it afloat, I don't see what would cause it's price to crash down to 0 over night.
"Gambling" has connotations of immoral behaviour, especially in zero-sum or always-lose scenarios like poker and casinos. I don't think it's fair to describe educated and informed investment or buy-ins with words like that. I think "risky venture" is a less loaded, more neutral, term to describe it instead.
As it is, I don't see Bitcoin and other currencies as true investments - just yet - I see the surge in Bitcoin mainly as a "distributed Ponzi-scheme" instead: those who are cashing-out now are those who bought-in early and being paid by the people buying it now - and the people buying it now expect more other people to buy into it later, pushing the price higher while supply and availability dwindle (owing to BTC's 28M cap). However, unlike a Ponzi-scheme, Bitcoin, Ethereum and others do have utility as a means of moving money around independently of existing, often state-controlled, bank networks or remittance services - and eventually Bitcoin will be the tool of choice for that - and when the tens of millions of people wanting to move money around do so is when we will know the real, unhyped, value of Bitcoin - until then, the question is if $7,000 USD/BTC is an obscene over-valuation, or is still comically low - and I don't know which side to believe.
We'll get a better idea when, or if, legacy companies like Western Union and SWIFT get involved - or when real-time BTC transactions cost less than a VISA or Mastercard transaction (say ~3%). Right now a 250 byte transaction will cost 54,240 satoshi ($3.83) and take 30 minutes to get the first confirmation - making it totally unacceptable for retail purchases, for example. Hopefully when the Lightning Network or other solutions get finalized we'll start to see some real traction, but how many bubbles will burst before then?
(Disclaimer: I'm a HODLer of BTC and ETH).
This is not a repeat from every bubble ever. This time it's different!
Bitcoin may well be in a bubble, but it isnt mathematically and legally guaranteed to decrease in value overall as compared to what most people consider traditional forms of "gambling".
I say as long as you follow centuries-old investment advice (diversify, always have a backup plan, have enough cash for a crash), there's no reason not to explore a new investment instrument. AKA, "fuck it, why not?"
Depending on how much you make I don't see why not invest "only $1000," as long as your other tested investment instruments are already qualified (emergency savings, 401k/roth/whatever, stocks, bonds, int'l investments).