I think you should wait for the bitcoin value to go down a bit and then start investing in bitcoin because that may really help you get some bitcoin to invest in it more so you can buy the things you want.
Bitcoin price is unpredictable we do not know what will happen with the value of Bitcoin in the next day. But if you see the current popularity of Bitcoin that has reached a new value, it is difficult to predict when Bitcoin will go down. Better to invest now because Bitcoin's value will go up.
Yes its true bitcoin price is unpredictable so when you've had a chance to buy a bitcoin of your own then why not. If bitcoin is on dumped state then i think its a time to buy a voin, but if its in pumped state then you should wait. And for your question if you wait or invest all i can say is anytime could be a great time to invest unless you can afford to invest because Bitcoin is a good investment.