[SM] Have you got a bottle of gin handy? Add a couple of dashes to a G & T and you get pink gin. Used to be very popular in the '60s when I used to work behind a bar.

Gin could be arranged, although it's not something I normally drink. But plainly I could buy a couple of crates of gin and the bitters would still outlast them. And a bottle of gin would lakst me 3-6 months. Y'know, I was viewing using up this bottle of bitters as a challenge, but unless I really go for it, which is sort of cheating, I don't think I'm going to manage it in my remaining lifespan.

Pink gin and water is also nice. 2 or 3 drops added to a ginger beer is one of my favourite very, very low alcohol drinks. Oh, and one of the several versions of rock shandy is 50/50 ginger ale and soda water, with a few drops of bitters.
A bit of searching and I've found culinary uses at this site

Bitters added to lemonade cuts some of the sweetness and makes a nice summer garden drink.

Is it any good for cleaning shower heads?

[pen] Only if it can dissolve the dead spiders.

That 'Shakespeare in Crescent' game we've just had brought to our notice was pretty good. We must do that again.

[Simons Mith] When I was a student, one of the drinks of choice at the time was a long vodka which consisted of a few drops of bitters smeared round a highball glass, ice, a shot of vodka, a dash of lime and topped up with soda water. A bit girly but very drinkable.

(nfras) How does that help achieve the main objective of student drinking which is to get pissed as quickly and cheaply as possible, then as now?

[INJ] I'll second anything in iambic pentameter!

[Rosie] Well, it's a cheap drink. No charge for bitters or soda, normally. When my dad was in the Royal Navy, it was traditional for midshipmen, and some other low-ranking officers, to drink pink gin, as all you paid for was the gin - hence it was the cheapest drink in the Officers' Mess - because midshipmen were so lowly paid.

(Phil) Didn't they have grog? Maybe not often enough. When I was a student we only drank spirits if we were deliberately trying to get as pissed as possible because in those days a shot of spirits was nearly twice the price of a pint of beer. In today's money I'd estimate the prices as £2 and £3.50.

When I was at Uni (mid-late 90s) my University Union used to do a happy hour. 50p a pint (the usual price at the time in a pub was £1-£1.25 depending on the brand). At about quarter to seven you'd see the bar packed with students buying 4 or 6 pints at a time. They would take them back to their table and drink them over the next couple of hours. You might think that the beer tasted awful after sitting in a glass for over an hour, and you'd be right. But it was cheap.