The most times I saw The Cure was in 2016 (six times). Currently I have a good job, no kids and live in a very good location in Europe (Bratislava) that allows me to travel anywhere... so, for now, I am able to follow the band pretty much everywhere in Europe with the following considerations:
1) I don't pay €100 or more if the band plays in a festival. That sum of money is reserved for only-Cure shows
in special venues.
2) I avoid travelling to the UK (as a Peruvian, and because UK does not belong to Schengen, I need to apply for a tourist visa which is nearly €200 on top of my expenses). Unless The Cure is playing a very special gig, UK is no-go for me.
3) For accommodation I stay at friend's or youth hostels. This helps me to save money.
As for the 2016 tour expenses:
TicketsWien € 70
Praha € 66
Hamburg € 71,11
Berlin € 0 - courtesy of a fellow curefans.com member

Bologna € 67,11
Roma € 100 (resale)
That makes €374 in concert tickets.
Accommodation and foodIn each city I stayed only one night (except Hamburg - 2 nights), food and accommodation per day would be worst case €100, that makes €700 for the cities above.
TransportTo go to Praha I went with curefans.com's jakso by car and I returned with him, I think I helped with the fuel so maybe spent €20 in transport.
From Bratislava to Bologna and then Rome and then back to Bratislava, I probably spent about €150.
To go to Hamburg, then train to Berlin then plane back to Bratislava, probably around €200.
Finally, round trip train from Wien to Bratislava is €15
That makes 20+150+200+15 = €385 in transport.
In SummaryI spent 374+700+385 = € 1500. This figure is an estimate, and you can add + - € 200 to this sum (souvenirs, etc.)
As how I pay this, I usually pay 50% from my debit card and the other 50% from my Diners card. I think I can lower these expenses if I organize carefully my trip in advance.
By the way, if The Cure ever plays in Bratislava, you all have free accommodation
