Learn Turkish: Bu bilet elli lira. - This ticket is fifty lira.

In Turkish, the verb 'to be' for the third person (he/she/it) is often just a suffix, and in everyday speech, it is usually dropped completely. So, placing the subject Bu bilet and the price elli lira next to each other is enough to mean 'This ticket is fifty lira.'

Why is lira singular? Shouldn't it be plural since it is fifty lira?

In Turkish, nouns that come right after a number are always kept in their singular form. You never add the plural suffix -lar or -ler after a number, so it is simply elli lira.

I am learning about var (there is). Why don't we use it here?

The word var means 'there is' or 'exists.' It is not used to link a subject to its description or price. You would use var if you wanted to say 'There is fifty lira' (Elli lira var). But to say 'This ticket is fifty lira,' you just state the item and the price without var.