Which makes any cost comparisons meaningless. Also to be factored in is that SR has been around for 20 years.
How the real world compares prices:
Over time:
Over time, you dig out the CPI stats (the US has them since 1913...The UK has them for much longer...) and calculate a given amount of currency that way. It takes some work if you're dealing in multiple currencies, or over significant amounts of time, but it is doable.
Between currencies:
The favorite way to do this is not to use official exchange rates, but instead to use PPP.
Purchasing Power Parity. How much of a given currency nets you a certain "basket" of goods. Take, for example, the
Big Mac Index popularized by
The Economist. It works, roughly.
In Shadowrun, it is impossible to compare currencies. You have no idea what things cost in any currency that you might put into a basket of goods. You have no idea what basic staples cost, for instance.
Fortunately, mostly you don't need to.
What I recommend: 1

is equal to $1 USD as of 1989. Inflate accordingly.