i can see were your coming from so with out knocking any body le me show you were im coming from...
crane retro cam summit price about $430
flat tappet cam with lifters $260 difference of $170 more for roller
OP needs to replace springs if going with a more aggressive cam for this build not much spring needed.will call it $80 not part of the cost of going roller compared to flat tappet.
retainers... also stock would work with this performance level but if you replaced them it would be apart of the cost to do the job any way call it $60
locks...still depending on retainers and condition these could or may not be replaced at this level. still a part of the cost of doing a good job with or with out roller call it $40
push rods...if the OP planned on doing roller rockers anyway then these need replace any way. no extra here either call it$150 and this is for good ones not needed for this level of build.
gasket are necessary for this build if a valve job is performed call it $50 still not part of doing a roller.
timing set same here not a part of going roller at this level call it $70
rockers OP said he was doing anyway but you can still use stock stamped steel (factory) but at any level of performance still not a part of putting in a roller. call it $500 but there are way cheaper then this that will work at this performance level.
converter...OP said he was going to change this anyway but still not necessary at this level but a good idea. call it $200.
any machine shop work necessary for this performance level with a roller lifting in the .500 range is minimal ill call it $200 dollars and it might be needed depending on the condition of the heads.
any work on the head for funny geometry at a machine shop ill call that 100 dollars but this can be done at home if you have the skills and the tolling to do it would be apart of your skill level
so if you add what it take over the cost of a flat tappet cam (at least if your using crane cams) I'm going to say the necessary cost would be $170 plus $200 making it $370 there may be some things that are unavoidable and many variables but i don't see these as being much more over a flat tappet cam.
I'm not sure if crane is the best to go with for your machine i prefer comp myself but for the money i think you can see what i am saying
this is not a knock on any body or there skill level so please take it that way.this is just to point out that its not that big of a adventure depending on what your trying to achieve and if your racing for real and your class allows the use of a roller you better bet your running against them and might want to consider what it takes to get there. this does not mean that you must absolutely have one to race or be on the street. there are many other factors like money just for one.