The probability of OSRS GP obtaining a whip within a 75-125 kill range is possible although not tipacal. possible. There is a greater possibility of getting it in the 1-540 range. However, you may never get one. Also, if you inquire about why people train slayers, it's almost always for the large drops. Examples: whips made from abby deamons, sols from ice strykewyrms etc.

Even if they slay for those drops most of their revenue won't come from them in particular on ice wyrms as they can drop amazing amounts, the SOL is only a minor extra. The 1/540 result is derived from an normal dropped (mite be 520 but I'm not sure) however, it is derived from players who report how many kills are required to get a whip, in fact, you could get the range you want, but this isn't the drop rate.

Helm of Neitiznot It's a fantastic balanced helm. Verac's or Torag's helm for more defensive stats . Or a Fighter hat for offensive stats (about exactly the same statistics as the Rune full helm, but bonuses in the Stab, Slash and Crush attack styles)

Guthans Plate - decent The cheap OSRS gold Fighter torso offers an impressive Strength bonus, which is an ideal alternative if you're not able to afford Bandos; also I'm not completely certain about this but I believe torag's (and Dharok's) offers slightly better defense and is at 650kish, so it's worth getting imo.