Ok, so let's just take a look at each leg of your trip and see whether it will help you make your mind regarding dilemma pass vs. point-to-point
However before that it maybe seems to think about switching a bit sequence of destinations, thus make it Berlin to Prague, then to Krakow, then Tatras (do you have specific place in mind?) and Budapest - Slovenia - Croatia
Berlin to Prague: on this route German Railways (DB) offer discounted tickets starting from 29 euro per person, although such tickets need to be purchase in advance, since they are limited per each departure. Full standard fare for train ticket here is 66 euro. Also pretty good, at least in terms of money, options offered by bus companies, on certain occasions you can find promo offer bus tickets Berlin to Prague for like 9 euro
Prague to Krakow: two options here - you can either travel by direct overnight train or travel during the day with change. For the overnight train Czech Railways (CD) offer purchasable online discounted tickets for as low as 19 euro (while full standard fare when buying in Prague is 42 euro). With daytime options you can as well travel relatively cheap (here you can choose either EuroCity train from Prague to Katowice & then domestic Polish train to Krakow or domestic Czech train from Prague to Cesky Tesin, cross the border to Poland by foot and take bus to Krakow from Polish part (Cieszyn) of the town)
Regarding "Tatras" you have to be more specific, because it's difficult to say something without knowing what you mean
However doubt that any journey to the mountains from Krakow (or Prague) will cost you let's say more than 20 euro
Budapest to Lake Bled: here you have three options: a) use direct everyday daytime through carriage Budapest-Zagreb-Ljubljana (39 euro for one-way ticket, no need to buy in advance), while Ljubljana to Lake Bled (again there are quite a few towns/villages there) is already easy and cheap; b) twice a week during summer there will be direct overnight train Budapest-Ljubljana-Koper (goes directly from Hungary to Slovenia avoiding Croatia), it's more expensive (standard full fare tickets is almost 53 euro), although conveniently arrives to Ljubljana in the morning; c) it is as well possible to travel to lake Bled region via Austria, meaning Budapest to Vienna (tickets from 13 euro when bought in advance), then Vienna to Villach (tickets from 19 euro when bought in advance) and another 10 euro for Villach to Bled (no need to buy ticket in advance)
Lake Bled to Croatia: again makes sense to be more specific regarding place/destination in Croatia, but saying in general the idea is to travel from Bled to Ljubljana and then take a train - either to Zagreb (16 euro), Rijeka (16,2 euro) or even Pula, also plenty of buses from Slovenia to Croatia, especially during summer
p.s. if you are not a fan of switching destinations sequence in the early part of your itinerary, then it's totally ok, everything can be done your way, however currently there is no direct train from Berlin to Krakow (instead there is bus connection, tickets start form 29 euro) and from Krakow it's a bit difficult to get cheap ticket to Prague since Polish Railways still doesn't sell discounted tickets Poland-Czech Republic online via website